The present invention relates to a squeegee device for the treatment of sheet material with liquid, viscous or powdery substances. More particularly the invention is directed at an apparatus for screen printing machines employing a side plate which limits the supply of ink.
The apparatus of the present invention being positioned at each side of a squeegee device, serves the purpose of preventing sideway movement of the ink material to be treated. Particularly when screen printing with rotary screens is involved, the apparatus of the present invention is absolutely necessary, as otherwise the ink or the like, collects in the marginal areas and is taken along by the rotating screen; as a result, coating errors occur because the ink can get behind the squeegee and can also drip off from above.
Equipment which had been used hitherto had a number of disadvantages. Firstly, it was positioned in the coating area and is adjacent to the support or the screen for a distance as far as the ink supply ought to reach. Attachment of prior art equipment was around a point of rotation of a support, this, however, loaded the support with its own weight. Furthermore, movement of the equipment on its support, particularly on rotary screens or on flat screens used with screen printing, entailed a considerable amount of abrasion. Also when rotary screens are used, the screen broke easily. Lastly, the apparatus of the prior art being adjacent to thin-walled rotary screens, can easily damage the latter during insertion and demounting.